Yes. First I removed the cogwheels and replaced and relocated the servo that turns the head sidewise with a standard size servo. Then I modified the hinges to the jaws to be able to move the jaw servo away. After that there was room for the rest. The Raspberry is mounted upside down under the Ardino. I took the speaker element from Roxcore Portasond speaker and made a separate speaker box that is monted behind the jaw. The amplifier was put in a separate box at the back of the head. The USB soundcard is mounted on the side of the bracket holding the Raspberry / Arudino. The servos for the eyes are mounted on the same brackets. The eye mechanism is also redesigned, based on some animatronic heads that I have seen. I will publish the changes on Thingiverse soon.

I'll be really interested to see your changes on Thingiverse. I felt from the start that much of the head space is wasted with such a large servo in there. Plus the wiring from my eye cameras runs the risk of getting caught in the jaw mechanism.

I have made a post http://www.thingiverse.com/thing:992918 that shows the modified parts of the InMoov head. I will make more posts with the parts that I have created or used to mount the Raspberry / Arduino and other electronics. I'm waiting for parts to finish the modified eye mechanism.

All the outer parts are unchanged on the exterior. The inside of the two neck parts are modified to allow for a standard size servo to be mounted. The jaw may have to be reprinted. The top of the skull still fits, but the part that hold the skull together has to be replaced, since the original is part of the servo holder. All the parts that needs to be reprinted if you already have built the head are in this post: http://www.thingiverse.com/thing:992918.

I will write better instructions there.

If you want to use the space freed up for other things, like the speaker, you can still use the original eye mechanism.

But if you want to make all the changes that I have made, the you also need to use a different eye mechanism and reprint the parts around the eye. But still no modification to the exterior.